Integrated circuit packages typically comprise at least one leadframe and at least one integrated circuit die. The integrated circuit die is generally mounted on a die pad of the leadframe and contacts on the die are usually electrically connected to leads of the leadframe. These leads may also be electrically connected to other circuitry inside or outside the integrated circuit package. The die and portions of the leadframe are usually encapsulated in an epoxy mold compound. Since integrated circuit packages are used for many different purposes, there are many different types of integrated circuit packages.
Most leadframes are formed on a single, thin sheet of metal as by stamping or etching. Multiple interconnected leadframes may be formed on a single leadframe sheet. Leadframes on the sheet are usually arranged in rows and columns. Usually die mounting, die to lead attachment (e.g. wire bonding) and epoxy encapsulation take place while the leadframes are still integrally connected on the leadframe sheet. After such processes are completed, the leadframe, and sometimes the encapsulation material, are severed (“singulated” or “diced”) with a cutting tool, such as a saw or laser. These singulation cuts separate the leadframe sheet into separate integrated circuit packages, each typically including at least one leadframe, at least one die, electrical connections between the die and leadframe (such as gold or copper bond wires) and the plastic material which encapsulates at least part of these structures.
One common type of integrated circuit packages is “SOP” (Small Outline Packages) in which leads protrude from opposite sides of the encapsulated portion of the package. Another common type is known as “QFP” (Quad Flat Packages). In QFP, the leads protrude outwardly from four lateral sides of the encapsulated portion of the package. The protruding leads in, for example a Gull Wing type SOP, may be bent into an appropriate shape after the integrated circuit package has been severed from the leadframe. Such integrated circuit packages are often used in surface mount technology (“SMT”) in which the leads extending from the sides of the package are soldered to surface contact portions of a printed circuit board or the like.